Explorer Achievement

Does anyone have any tips on how to complete these explorer achievements? For example I have 173/175 Krytan areas...is there any way to tell which 2 I'm missing or do I have to just search everywhere around Kryta again?

Go to the wiki and look at the maps of the area. As the explorer achievement is about uncovering all the areas named in white writing on the map, such as Cornucopian Fields etc, then it's easy to compare the areas you've unlocked to areas on the wiki's maps.

It's most likely to be the jumping puzzle areas however, or one of a few hidden places.